Variable inclination back support



Sept. 25, 1962 J. AGIMAN VARIABLE INCLINATION BACK SUPPORT 2 Sheets-Sheet v 1 Filed Sept. l, 1959 gg E a 2 /////r// w Sept, 25, 1962 J. AGIMAN VARIABLE INCLINATION BACK SUPPORT Filed Sept. 1, 1959 2 Sheets-Shea?l 2 ite dta 3,055,019 VARIABLE INCLINATION BACK SUPPORT Jacques Agrnan, 8 Boulevard du Parc, Neuilly-sur-Seine (Seine), France Filed Sept. 1, 1959, Ser. No. 837,481 Claims priority, application France Sept. 23, 1958 2 Claims. (Cl. 5-71) The present invention relates to devices of the type having a backrest of variable inclination for a bed or a seat pivotally mounted on a fixed frame and operated by hydraulic control means adapted to vary the inclination of the backrest with respect to the fixed frame, these means including a pump mounted on one side of the frame.

In known devices of this kind, the hydraulic control means include a single jack interposed between the frame and the support, this jack being located on the side on which is located the pump. Such an arrangement has the drawback that the variable inclination backrest either must undergo undesirable deformations, or must be made of a heavy and costly construction. Furthermore, in the known devices, the pump sucks in liquid from a special reservoir, which increases the space occupied by the device `and the cost thereof.

In order to avoid any undesirable deformation of the support without increasing the dimensions of the device referred to above, -I make use, according to the present invention, of two hydraulic jacks disposed on the respective sides of the system formed by the variable inciination backrest and the frame, at least some of the elements It should be noted that the iixed frame of the device above referred to may be a part of `the frame of a bed, of an arm-chair, or the like, on which the variable inclination backrest is mounted, or may be a part of a special frame adapted to be tted on :a bed or the like.

Preferred embodiments of the present invention will be hereinafter described with reference to the accompanying drawings given merely by way of example and in which:

IFIG. l is an elevational view, with some parts in section, of -a device adapted to be mounted on a bed or the like;

FIG. 2 partly shows, in plan view, the same device, the

pump which serves to operate the hydraulic control device being removed;

FIG. 3 is a sectional elevational view, on an enlarged 55 scale, of the pump itself;

FIG. 4 is Ia sectional fragmentary view on line -IV-IV of FIG. l; f

FIG. 5 shows a second embodiment of the invention in which the hydraulic jacks and the pump are mounted directly on the frame of a bed;

FIG. 6 shows, in sectional view and on an enlarged scale, one of the rotary jacks of this second embodiment of the invention; and

FIG. 7 is an axial sectional view of the pump mounted 65 on one of the rotary jacks.

With reference to FIGS. 1 to 4, the device according to the invention comprises a fixed frame including a tube 1 bent in the general shape of an inverted U and two longitudinal tubes 3 parallel to each other and Secured 70 to the ends of tube 1 by two connecting pieces 4, respectively. The horizontal portion of tube 1 rests upon the 2' atet Patented Sept.. 25, 1962 transverse member 2 of a bed frame and the front ends of tubes 3 are secured by clamps S to the side members 6 of said bed frame.

The last mentioned ends of ilongitudinal tubes 3 carry, pivotally mounted thereon about pins 7, the ends of a U-shaped tube S. The two parallel branches of tube 8 form, together with stretched Wires Sa, the frame of a backrest for a person lying on the bed.

Between each of said parallel branches of tube 8 and the respective connecting piece 4 of the frame located on the same side thereof as said branch, I interpose a jack the piston element 9 of which is hinged at 10 to the tube 3 of the backrest, whereas the cylinder 11 of said jack is connected to the corresponding connecting piece 4 by a plug 12 (FIG. 4) closing the end of said cylinder 11 and through which extends, with a iluidtight t, a pivot 13 screwed, by its threaded end 14, into the corresponding piece 4. Fluid-tightness betwen piston 9 and cylinder 11 is obtained by means `of a packing :member 15.

ri`he two connecting pieces 4 are preferably identical to each other and on one of them there is mounted a pump the body 16 of which forms, at its upper part, a cylinder 17 in which is slidably fitted a plunger piston 18 provided with a packing ring 19 (FIG. 3).

This pump is provided with an inlet check-valve 20 mounted in `an intake conduit 21-22. Delivery of liquid from the pump takes place through a delivery conduit 23 provided with an outlet check-valve 24. Advantageously, for the sake of safety, the inlet check-valve 29' is by-passed by a discharge valve (not shown) .interposed between the portions 21 and 22 of the intake conduit. This discharge valve opens when, at the end of the maximum expansion movement of the jacks, the pressure of the liquid in the pump exceeds a maximum admissible value.

35 The pump cylinder, including the inlet and outlet checkvalves', is by-passed by conduits 25-26 which directly connect the intake conduit 22 of the pump with a space located downstream of the outlet valve 24. In these conduits 25-26 there is mounted a valve 27 urged against its seat by a spring 28. This valve can be opened by the piston 18 of the pump when this piston is in its lowermost position where it is in contact with an extension 2.9 rigid with valve 27.

The pump piston 1S is driven by means of a lever 30 adapted to be operated by a person lying upon support \8-8a. This lever is connected to the body 16 of the pump by a rod 31 and it is pivotally mounted by lug 32 on the upper end of piston 18.

When the pump is mounted on the corresponding connecting piece 4, the orifices through which delivery conduit 23 and by-pass conduit 25 open into the under face 33 of the pump body are both located opposite a blind hole 34 provided in piece y4. In this position, the aperture through which the intake conduit 22 opens into said under face 33 of the pump body is located opposite a second blind hole 3S also provided in piece 4.

Blind hole 34 communicates both with a conduit or passage 35 provided in the pivot 13 of the jack and With a conduit 37 passing through piece 4 and connecting blind hole 34 with the inside of tube 1 which connects the blind hole 34 of piece 4, on which is located the pump, to the piece 4 located on the opposite side of frame 1 3.

Passage 36 is itself constantly in communication with the inside of the jack cylinder `11 through a groove 38 provided in pivot 13 and a conduit 39 provided in plug 12 opposite this groove.

In View of the fact that the piece 4, located on the opposite side of the frame, does not carry a pump, and the jack 9, 11 mounted through its pivot 13 on said last mentioned piece 4 have the same construction as that described above (the blind holes 34-35 of the piece 3 4 on which the pump is not mounted being closed by a plate 4a), tube 1 insures, in combination with the two connecting pieces 4, a communication between the conduits 23-25 of pump 16 and the jack located on the opposite side `of the cylinder.

`Blind hole 35 communicates, through a conduit 40 CFIG. 1), with the inside of the tubular branch k3 of the frame which extends between one of the clamps 5 and the connecting piece 4 which supports pump 16. This tubular piece 3 contains the liquid that must be drawn by the pump when it is desired to increase the inclination of support -ga, and it receives the liquid delivered from the jacks when this inclination is reduced. In other words, this tubular branch 3 constitutes a liquid reservoir for the hydraulic control means. This branch tube 3 is provided with an orifice 41 serving to lill it with liquid and which may remain open. However, according to a preferred embodiment of the invention, the end of the reservoir constituted by branch tube '3 is closed, so that a cushion of air under pressure is formed at the upper end of this branch tube, this air cushion permitting an easier tilling of the pump during the suction stroke thereof.A

The device above described works as follows:

When the person that is lying on support 3-8a wishes to increase the inclination of this support, he operates the pump by means of lever 30 so as to cause liquid to flow from tubular branch 3 acting as a reservoir into the cylinders 11 of the jacks, so that the pistons 9 of these jacks are caused to project outwardly and to pivot support S-Sa upwardly, for instance from the position shown in FIG. 1 in solid lines to the position shown in `dot-anddash lines. When thus operating the pump, the person lying on the support does not move lever 3@ to the end of its downward stroke where piston 18 would cause the opening of valve 27. If this person wishes to reduce the inclination of backrest 8-8a, he brings piston 18 into the lowermost position where it causes the opening of valve 27, so that the pistons 9 are driven back into their cylinders 11 and liquid located in said cylinders is caused to flow through valve 27, conduit 22, hole 35 and conduit 40 into reservoir 3.

In the embodiment of the invention illustrated by FIGS. 5 to 7, backrest S-Sa is xed, at both of its ends, to the rotating elements 42 of two rotary jacks secured on either side of a frame 43 which, in this case, is the frame of a bed. The rotating element 42 of each of the jacks is mounted on a fixed element 44 of said jack in such manner as to rotate about the axis A of said element 44, said element 44 being itself xed to the frame 43 of the bed, for instance by means of screws 45.

The external shape of element v44 and the internal shape of element 42 of each of the jacks are arranged in such manner that between these two elements, on the inside of element 42, there are provided two free spaces 46-47, a cover 48 closing the jack at the front. In order to insure uidtightness in space 47, I may for instance provide in this space a bag 47a of an expansible material such as rubber.

Furthermore, one of the two rotary jacks is combined with a pump which advantageously, as shown, is in the form of a screw pump `and which is mounted coaxially with the fixed element 44 of this jack. Thus, the cylinder of this pump is constituted by a sleeve 49 rigid with ixed element 44 and provided with threads 50 cooperating with corresponding threads of a piston 51 provided, at its external end, with a hand-wheel 52.

The inner end of cylinder 49 communicates, through a conduit 53 provided in the fixed element 44 and through a passage 54, with the inside of space 417. This space 47, in turn, communicates, through a nozzle y55, a conduit 56 and a channel 57, with the inside of bent tube 8 Iat one of the ends thereof. The other end 8 of this tube com- 4 municates with the space 47 of the rotary jack located on the other side of the rbed but which is not provided with a pump. In this second mentioned jack, the cover 48 is advantageously rigid with an element analogous to element 44.

When piston 51 is screwed in cylinder 49, liquid is forced into the `spaces 47 of the two jacks since these two spaces communicate together through tube S. The delivery of liquid into these spaces produces a rotation of elements 42 with respect to xed elements 44, in such manner as to increase the angle of inclination of backrest S-Sa with respect to the frame 43 of the bed. If hand-wheel 52 is rotated in the opposed direction to move piston 51 outwardly, the person lying on backrest S-Sa causes this support to move downwardly and this movement is communicated to the elements 42 of the jacks in a direction such that a portion of the liquid contained in the spaces 47 of the jacks is driven into cylinder 49 the -available volume of which is increased due to the outward movement of piston 51.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and eicient embodiments of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What is claimed is:

1. Apparatus comprising a bed frame, a back rest pivoted to said frame and adapted for adjustable inclination with respect thereto, side members lixed to said frame, one of said side members being adapted to accommodate a fluid medium, connecting members supported on said side members, pump means supported on the connecting member on said one side member, first pivot means on the latter said connecting member and second pivot means on the other of said connecting members, a tube extendj ing across said bed frame and coupling said connecting members, and piston and cylinder combinations pivotally and extensibly coupled between said pivot means and said back rest, said latter connecting member being provided with a fluid path between said one side member and pump means, said latter connecting member and irst pivot means defining a fluid path between said pump means and the corresponding one of said cylinders, said other connecting member and tube and second pivot means defining a fluid path between said pump means and the other of said cylinders.

2. Apparatus as claimed in claim 1, wherein said pump means includes a piston and cylinder, inlet and outlet one-way valves operatively coupled to the latter said cylinder and respectively coupled to said one side member and to said irst pivot means Iand tube, a by-pass valve coupling said outlet valve to said one side member, and means on and responsive to a determinable stroke of the latter said piston to operate said by-pass valve.

References Cited in the ile of this patent UNITED STATES PATENTS 691,224 Wilkins Ian. 14, 1902 852,454 Ryan May 7, 7 l1,962,924 Bristol June 12, 1934 2,495,143 Simmonds Ian. 17, 1950 2,663,029 Whitley et al. Dec. 22, 1953 2,666,216 Schnaitter Jan. 19, 1954 2,788,529 Moritzacky et al. Apr, 16, 1957 `2,819,475 Ericsson Jan. 14, 1958 FOREIGN PATENTS 67,868 Switzerland Feb. 26, 1914 

